The present invention relates generally to a connector block, and more particularly, to a connector block having an isolation circuit for use as, for example, an alarm-isolation connector block at the central office of a telephone service provider.
Telephone service providers use distribution cables to route land-based telephone lines from the subscribers"" premises to a central location for connection with the telephone network. These central locations are called central offices and include a variety of telephone network equipment for functions such as electrical surge protection, back-up power generation, and generation of telephone records. Due to the number of central offices required in a telephone network, it is cost-prohibitive to man all of the central offices with employees. However, the telephone service provider generally desires to monitor the unmanned central offices.
Consequently, central offices are typically connected to a Network Operations Center (NOC) via a trunk cable. Employees of the telephone service provider at the NOC can monitor the building operations of several central offices from one location. For instance, central offices can include alarms for monitoring door alarms, low-fuel in the generator, and/or generator failures. These alarms are typically tied into a conventional connector block at the central office that is electrically connected to the NOC for monitoring by personnel. However, electrical feedback in conventional connector blocks can cause overloading of the circuit used to report abnormal conditions to the NOC.
The present invention is directed to a connector block having at least one alarm-isolation circuit including first and second alarm input terminals that are operable for electrical connection with respective wires of an alarm input. First and second alarm output terminals are, respectively, electrically connected to the first and second alarm input terminals. Additionally, at least one diode is electrically connected between the first alarm input terminal and the first alarm output terminal. Thus, forming a portion of the at least one alarm-isolation circuit capable of forwarding an electrical signal to a remote location when the alarm is activated.
The present invention is also directed to a connector block having at least one alarm-isolation circuit including first and second alarm input terminals that are operable for electrical connection with respective alarm inputs. A first and a second plurality of alarm output terminals each being, respectively, electrically connected to the first and second alarm input terminals. Additionally, a first and second plurality of diodes are, respectively, electrically connected between the first alarm input terminal and one of the first plurality of alarm output terminals and electrically connected between the second alarm input terminal and the one of the second plurality of alarm output terminals.
The present invention is further directed to a connector block having at least one alarm-isolation circuit including two alarm input terminals that are operable for electrical connection with a two wire alarm input. A plurality of alarm output terminals being electrically connected to one of the two alarm input terminals. A plurality of diodes are electrically connected to one of the two alarm input terminals, thereby inhibiting feedback between the plurality of alarm output terminals.
The present invention is also directed to an alarm-isolation circuit including a first and a second alarm input terminal that are operable for electrical connection with respective alarm inputs. First and second alarm output terminals are, respectively, electrically connected to the first and second alarm input terminals. Additionally, at least one diode is electrically connected between the first alarm input terminal and the first alarm output terminal. Thus, forming a portion of the alarm-isolation circuit capable of forwarding an electrical signal to a remote location when the alarm is activated.